As electronic devices have become high-performance and downsized in recent years, electronic components for use in the electronic devices have been also required to be smaller. Coil components such as inductors are no exception and have also been downsized by various design modifications.
For example, known coil components have been produced by inserting a metal core into the space inside a coil and then burying this coil and the core into a magnetic body by press molding. However, this method cannot reduce the “side gap”, which is a gap between the outer periphery of the coil and the side faces of the magnetic body, and thus cannot downsize the coil component. One way to solve this problem and downsize the component is, for example, a sheet press method disclosed in Japanese Unexamined Patent Application Publication No. 2011-3761. The sheet press method includes: sandwiching a plurality of coils between two magnetic sheets and pressure-bonding these coils and sheets; and dividing this into chips with a dicer.
The inventor of the present disclosure noticed that, in the case where a coil component (e.g., an inductor) is produced by the above-described sheet press method, the resulting inductor may have a groove in its side faces between the top and bottom magnetic sheets because of the coil sandwiched between the magnetic sheets.
The base body obtained by the sheet press method (that is, the base body constituted by the magnetic sheets and the coil sandwiched between the magnetic sheets) is then plated and thereby given outer electrodes. The outer electrodes are formed by: placing a mask on the surface of the base body except for the areas in which the outer electrodes are to be formed; and then pre-treating the base body with a conductive liquid and plating the base body. During this process, if the base body has a groove, a space results between the mask and the base body and the conductive liquid enters the space. As a result, the plating layer forms not only in the predetermined areas but also in other areas. If the plating layer forms in such other areas, the two outer electrodes may short-circuit. This is not preferred.